Add basic gemspec.

has_details.gemspec

@@ -0,0 +1,12 @@
+spec = Gem::Specification.new do |s|
+  s.name = 'has_details'
+  s.version = '0.0.1'
+  s.summary = "Attribute serialization for ActiveRecord."
+  s.description = %{HasDetails is a Rails plugin to allow you to serialize an arbitrary amount of (optional) attributes into a column.}
+  s.files = Dir['lib/**/*.rb'] + Dir['test/**/*.rb']
+  s.require_path = 'lib'
+  s.authors = %w(Marten\ Veldthuis Jason\ Weathered)
+  s.email = %w(marten@veldthuis.com jason@jasoncodes.com)
+  s.homepage = "http://github.com/jasoncodes/has_details"
+  s.add_runtime_dependency 'activerecord', %w(~>2.3.0)
+end